*{
    padding: 0;
    margin: 0;
}
p{
    font-family: "华文楷体";
}
a{
    text-decoration: none;
}
body{
    background:url("../imgs/lm3.jpeg") no-repeat center;
    background-attachment: fixed;
    background-size: cover;  

}

button{
    user-select: none;
}
.navbar-default{                /*导航栏 */
    background: rgba(0, 0, 0, 0.3);
}
.nav-signin,.nav-login{         /*导航栏登录与注册按钮 */
    width: 60px;
    height: 35px;
    margin: 5px 5px;
    border: 0 solid;
    border-radius: 5px;
}
.nav-login{
    background-color: rgb(127, 163, 241);
}
.nav-signin{
    background-color: rgb(194, 211, 47);
}

.cover {
    position: absolute;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.3);
    top: 0;
    display: none;
}

.login-outside{             /*用户登录界面外面div*/
    position: absolute;
    width: 450px;
    height: 500px;
    top: 50%;
    left: 50%;
    
    transform: translate(-50%,-50%);
    overflow: hidden;
    z-index: 99999;
    /* display: none; */
}
.form-control{
    background: rgba(0, 0, 0, 0.3);
    outline: none;
    color:whitesmoke;
    
}

.login-div,.signin-div{
    position: absolute;
    background-color: whitesmoke;
    background: rgba(255, 255, 255, 0.3);
    z-index: 99;
    text-align: center;
    border-radius: 10px;
    font-size: 16px;
    backdrop-filter: blur(4px);
    left: 0;
    z-index: 99999;
}

.login-div{         
    top: 0;                                 /*用户登录界面 */
    width: 450px;
    height: 350px;
    display: none;
    transition: top 0.2s;    
}


.signin-div{   
    top: 500px;             /*注册界面*/
    width: 450px;
    height: 500px;
    transition: top 0.2s;    
    /* display: none; */
}


 .login-div input,.signin-div input{                              /*用户登录界面 */
    margin: 20px;
    width: 200px;
    height: 30px;
    border-radius: 5px;
    outline: none;
    background: rgba(0, 0, 0, 0.1);
    border: 1px solid black;
}

.login-div button,.signin-div button{                              /*用户登录界面按钮 */
    margin: 20px;
    width: 90px;
    height: 35px;
    border-radius: 5px;
    border: 1px solid black;    
    user-select: none;
}
.login-div .bt1,.signin-div .bt2{                                /*用户登录界面登录按钮 */
    background: rgba(102,177,255,0.5);
}
.login-div .bt1:hover,.signin-div .bt2:hover{
    background: rgba(58, 143, 233, 0.5);
}



.login-div .cancle,.signin-div .cancle2{
    background:rgba(199, 229, 231,0.3);     /*用户登录界面取消按钮 */
}
.login-div .cancle:hover,.signin-div .cancle2:hover{           
    background:rgb(199, 229, 231);
}

.login-div a,.signin-div a{                                   /*用户登录界面链接 */
    color: rgb(93, 84, 109);
    text-decoration: none;
    margin: 0 10px;
}


.welcome{           /*欢迎页面*/
    position: relative;
    width: 98%;
    height: 600px;
    background: rgba(0, 0, 0, 0.1);
    left: 50%;
    transform: translate(-50%,0);
    border-radius: 5px;
}

.welcome-card{
    position: absolute;
    width: 100%;
    height: 200px;
    top: 50px; 
    /* background-color: #fff; */

}

.welcome-words{
    position: absolute;
    color: whitesmoke;
    text-align: center;
    line-height: 100px;
    width: 600px;
    height: 100px;
    /* height: 200px;
    width: 200px; */
    font-size: 40px;  
    left: 50%;
    top: 50%;
    transform: translate(-50%,-50%);
    border: 1px solid whitesmoke;
    user-select: none;    
}

.welcome-words::before,.welcome-words::after{
    content: '';
    border: 2px solid whitesmoke;
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    margin: -15px;
    animation: borderClip 8s linear infinite;
}
.welcome-words::after{
    animation-delay: -4s;
}

/* 628*128 */
@keyframes borderClip{
    0%,100%{
        clip: rect(0px,628px,2px,0px);    
    }
    25%{
        clip: rect(0px,2px,128px,0px);
    } 
    50%{
        clip: rect(126px,628px,628px,0px);
    }
    75%{
        clip: rect(0px,628px,128px,624px);
    }
}

.welcome-passage{
    position: absolute;
    width: 600px;
    height: 100px;
    left: 50%;
    transform: translate(-50%,0);
    bottom: 40%;
    text-align: center;
    font-size: 18px;
    color: whitesmoke;

}


.down{
    position: absolute;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: 2px solid whitesmoke;
    bottom: 5px;
    left: 50%;
    transform: translate(-50%,0);
    cursor: pointer;
    text-align: center;
    font-size: 30px;
    color: whitesmoke;
    font-weight: 400;
    
}
.down:hover{
    box-shadow: 0px 0px 30px 5px whitesmoke;
}

.narrow{
    width: 16px;
    height: 16px;
    position: absolute;
    border-left:2px solid whitesmoke ;
    border-bottom:2px solid whitesmoke;
    transform: rotate(-45deg);
    left: 50%;
    top: 50%;
    margin-top: -11px;
    margin-left: -8px;
}

.navbar-nav-left li:hover{
    background: rgba(0, 0, 0, 0.3);
}

.article-outside{
    position: absolute;
    width: 704px;
    display: inline-block;
    display: -webkit-flex;
    display: flex;
    height: 425px;
    left: 100px;
    margin-top: 85px;
    background-color: #fff;
}
.article-header{
    width: 704px;
    height: 63.4;
    background-color: #fff;
    padding: 18px 20px;
}
/* 
.class-nav{
    position: absolute;
    width: 150px;   
    height: 220px;
    background-color: #fff;
    display: inline-block;
} */


#narrow{
    transition: all 1s;
}

